surgical-fixation-sternal-fractures-preoperative-planning-safe

Surgical Fixation of Sternal Fractures: Preoperative Planning and a Safe Surgical Technique Using Locked Titanium Plates and Depth Limited Drilling

Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the ...

University Hospital Erlangen

Traumatic instability of the sternoclavicular joint is a rare condition. It can be treated by surgical cerclage fixation, which necessitates postoperative immobilization, an approach preventing early postoperative functional rehabilitation. Balser plate stabilization is a therapeutic alternative that does not require extended periods of immobilization. From January 1, 1996, to December 31, 2000, a total of 10 trauma patients with unstable sternoclavicular joints (Allman grade III) requiring surgical management were treated with Balser plate stabilization to allow early physiotherapy. The population included 7 patients with anterior dislocations, 2 with posterior dislocations, and 1 with medial epiphysiolysis in addition to posterior dislocation. Implants were removed from 9 patients after 3 months and 1 patient after 2 months. One year or longer after the procedure, 9 of 10 patients were available for follow-up; 1 patient had moved. The results achieved with this alternative treatment are excellent. There were no cases of redislocation. The only surgical complication was a seroma that required surgical drainage. One patient had arthrosis develop. Outcome was assessed with Constant (range, 84-100; mean, 90.2 +/- 6.6) and DASH (disabilities of the arm, shoulder, and hand) (range, 4.1-16.6; mean, 8.4 +/- 1.4) scores. For the rare case of sternoclavicular joint dislocation requiring open surgical reduction and stabilization, the Balser plate technique is reliable, permits early movement, has good postoperative results, and compares favorably with alternative methods.

Balser plate stabilization: an alternate therapy for traumatic sternoclavicular instability.

The aim of the study was to retrospectively determine the potential for radiation dose reduction at multidetector computed tomography (CT) of the paranasal sinus by using computer simulation of the effect of low-radiation dose acquisition on diagnostic image quality. This HIPAA compliant study was approved by the institutional human research committee. The need for informed patient consent was waived. Twenty patients underwent four-section CT at 120 kV, 170 mAs, and 4 x 1-mm collimation. Artificial image noise was added to the CT raw data by using a dedicated software platform. Acquisitions with effective tube currents of 134, 100, 67, and 33 mAs were simulated. Each raw data set was reconstructed with bone and soft-tissue algorithms, and two radiologists independently rated the images in blinded fashion. A two-sided paired Student t test was used for statistical analysis. The lowest radiation dose that still provided diagnostic quality was <or=67 effective mAs for osseous structures and <or=134 effective mAs for the optic nerve and the inferior rectus muscle. On the basis of the results, tube currents can be lowered and radiation dose reduced by 20%.

Multidetector CT of the paranasal sinus: potential for radiation dose reduction.

Chondrocytes have to withstand considerable hypoxic conditions within the avascular articular cartilage. The present study investigated the effects of inhibiting or stabilizing hypoxia-inducible factor (HIF)-1 alpha by 2-methoxyestradiol or dimethyloxaloylglycine on the progression of osteoarthritis in murine knee joints.

Role of hypoxia-inducible factor 1 alpha in the integrity of articular cartilage in murine knee joints.

The purpose of this article was to evaluate the potential of in vivo zonal T2-mapping as a noninvasive tool in the longitudinal visualization of cartilage repair tissue maturation after matrix-associated autologous chondrocyte transplantation (MACT). Fifteen patients were treated with MACT and evaluated cross-sectionally, with a baseline MRI at a follow-up of 19.7 +/- 12.1 months after cartilage transplantation surgery of the knee. In the same 15 patients, 12 months later (31.7 +/- 12.0 months after surgery), a longitudinal 1-year follow-up MRI was obtained. MRI was performed on a 3 Tesla MR scanner; morphological evaluation was performed using a double-echo steady-state sequence; T2 maps were calculated from a multiecho, spin-echo sequence. Quantitative mean (full-thickness) and zonal (deep and superficial) T2 values were calculated in the cartilage repair area and in control cartilage sites. A statistical analysis of variance was performed. Full-tickness T2 values showed no significant difference between sites of healthy cartilage and cartilage repair tissue (p < 0.05). Using zonal T2 evaluation, healthy cartilage showed a significant increase from the deep to superficial cartilage layers (p < 0.05). Cartilage repair tissue after MACT showed no significant zonal increase from deep to superficial cartilage areas during baseline MRI (p > 0.05); however, during the 1-year follow-up, a significant zonal stratification could be observed (p < 0.05). Morphological evaluation showed no significant difference between the baseline and the 1-year follow-up MRI. T2 mapping seems to be more sensitive in revealing changes in the repair tissue compared to morphological MRI. In vivo zonal T2 assessment may be sensitive enough to characterize the maturation of cartilage repair tissue.

Quantitative T2 mapping during follow-up after matrix-associated autologous chondrocyte transplantation (MACT): full-thickness and zonal evaluation to visualize the maturation of cartilage repair tissue.

Moxifloxacin is a fluoroquinolone with a broad spectrum of activity and good penetration into many tissues, including bone. Penetration of moxifloxacin into bone has not yet been studied using compartmental modeling techniques. Therefore, we determined the rate and extent of bone penetration by moxifloxacin and evaluated its pharmacodynamic profile in bone via Monte Carlo simulation. Twenty-four patients (10 males, 14 females) undergoing total hip replacement received 400 mg moxifloxacin orally 2 to 7 h prior to surgery. Blood and bone specimens were collected. Bone samples were pulverized under liquid nitrogen by a cryogenic mill, including an internal standard. Drug concentrations were analyzed by high-performance liquid chromatography. We used ADAPT II (results reported), NONMEM, and WinBUGS for pharmacokinetic analysis. Monte Carlo simulation was performed to reverse engineer the necessary area under the free concentration-time curve fAUC(SERUM)/MIC in serum and total AUC(BONE)/MIC in bone for a successful clinical or microbiological outcome. The median (10% to 90% percentile for between-subject variability) of the AUC in bone divided by the AUC in serum (AUC(BONE)/AUC(SERUM)) was 80% (51 to 126%) for cortical bone and 78% (42 to 144%) for cancellous bone. Equilibration between serum and bone was rapid. Moxifloxacin achieved robust (> or = 90%) probabilities of target attainment (PTAs) in serum, cortical bone, and cancellous bone up to MICs of < or = 0.375 mg/liter based on the targets fAUC(SERUM)/MIC > or = 40 and AUC(BONE)/MIC > or = 33. Moxifloxacin showed high bone concentrations and a rapid equilibrium between bone and serum. The favorable PTAs compared to the 90%-inhibitory MIC of Staphylococcus aureus warrant future clinical trials on the effectiveness of moxifloxacin in the treatment of bone infections.

Penetration of moxifloxacin into bone evaluated by Monte Carlo simulation.

Amoxicillin (amoxicilline)-clavulanic acid has promising activity against pathogens that cause bone infections. We present the first evaluation of the bone penetration of a beta-lactam by population pharmacokinetics and pharmacodynamic profiling via Monte Carlo simulations. Twenty uninfected patients undergoing total hip replacement received a single intravenous infusion of 2,000 mg/200 mg amoxicillin-clavulanic acid before surgery. Blood and bone specimens were collected. Bone samples were pulverized under liquid nitrogen with a cryogenic mill, including an internal standard. The drug concentrations in serum and total bone were analyzed by liquid chromatography-tandem mass spectrometry. We used NONMEM and S-ADAPT for population pharmacokinetic analysis and a target time of the non-protein-bound drug concentration above the MIC for > or = 50% of the dosing interval for near-maximal bactericidal activity in serum. The median of the ratio of the area under the curve (AUC) for bone/AUC for serum was 20% (10th to 90th percentile for between-subject variability [variability], 16 to 25%) in cortical bone and 18% (variability, 11 to 29%) in cancellous bone for amoxicillin and 15% (variability, 11 to 21%) in cortical bone and 10% (variability, 5.1 to 21%) in cancellous bone for clavulanic acid. Analysis in S-ADAPT yielded similar results. The equilibration half-lives between serum and bone were 12 min for amoxicillin and 14 min for clavulanic acid. For a 30-min infusion of 2,000 mg/200 mg amoxicillin-clavulanic acid every 4 h, amoxicillin achieved robust (> or = 90%) probabilities of target attainment (PTAs) for MICs of < or = 12 mg/liter in serum and 2 to 3 mg/liter in bone and population PTAs above 95% against methicillin-susceptible Staphylococcus aureus in bone and serum. The AUC of amoxicillin-clavulanic acid was 5 to 10 times lower in bone than in serum, and amoxicillin-clavulanic acid achieved a rapid equilibrium and favorable population PTAs against pathogens commonly encountered in bone infections.

Bone penetration of amoxicillin and clavulanic acid evaluated by population pharmacokinetics and Monte Carlo simulation.

Recent data have suggested a relation among long-term endurance sport practice, left atrial remodeling, and atrial fibrillation. We investigated the influence of an increased vagal tone, represented by the early repolarization (ER) pattern, on diastolic function and left atrial size in professional soccer players. Fifty-four consecutive athletes underwent electrocardiography, echocardiography, and exercise testing as part of their preparticipation screening. Athletes were divided into 2 groups according to presence or absence of an ER pattern, defined as a ST-segment elevation at the J-point (STE) > or =0.1 mm in 2 leads. For linear comparisons average STE was calculated. Mean age was 24 +/- 4 years. Twenty-five athletes (46%) showed an ER pattern. Athletes with an ER pattern had a significant lower heart rate (54 +/- 9 vs 62 +/- 11 beats/min, p = 0.024), an increased E/e' ratio (6.1 +/- 1.2 vs 5.1 +/- 1.0, p = 0.002), and larger volumes of the left atrium (25.6 +/- 7.3 vs 21.8 +/- 5.0 ml/m(2), p = 0.031) compared to athletes without an ER pattern. There were no significant differences concerning maximum workload, left ventricular dimensions, and systolic function. Univariate regression analysis revealed significant correlations among age, STE, and left atrial volume. In a stepwise multivariate regression analysis age, STE and e' contributed independently to left atrial size (r = 0.659, p <0.001). In conclusion, athletes with an ER pattern had an increased E/e' ratio, reflecting a higher left atrial filling pressure, contributing to left atrial remodeling over time.

Early repolarization, left ventricular diastolic function, and left atrial size in professional soccer players.

Prolonged hospitalization is known to be associated with a loss of cognitive performance. Does playing video games (VGs) developed to improve cognitive properties delay this loss or even lead to an increase in cognitive performance? We performed a 10-day longitudinal study of patients who received total hip arthroplasty. We compared 16 patients (6 male) aged 66 ± 9 years (mean ± standard deviation) who played Dr. Kawashima's Brain Training: How Old Is Your Brain? (Nintendo; Redmond, Washington) on a Nintendo DS handheld console with 16 control patients (6 male) aged 69 ± 14 years. We measured cognitive performance 1 day preoperation, as well as on days 2 and 9 postoperation. With the daily exercise of a specific VG by the play group, the patients' fluid intelligence (median intelligence quotient 99-106), working memory capacity, and rate of information processing significantly improved over the course of 7 postoperative days. The cognitive performance of the control group did not increase. However, the memory spans of both groups did not systematically change. Exercise with VGs can prevent the loss of cognitive performance during prolonged hospitalization.

Stop of loss of cognitive performance during rehabilitation after total hip arthroplasty-prospective controlled study.

To investigate the effect of chondromodulin 1 on the phenotype of osteochondral progenitor cells in cartilage repair tissue.

Chondromodulin 1 stabilizes the chondrocyte phenotype and inhibits endochondral ossification of porcine cartilage repair tissue.

This study investigated the effect of thrombospondin-1 (TSP-1) on the formation of cartilage repair tissue in combination with stimulation by osteogenic protein-1 (OP-1). In miniature pigs, articular cartilage lesions in the femoral trochlea were treated by the microfracture technique and either received no further treatment (MFX), or were treated by additional application of recombinant osteogenic protein-1 (MFX+OP-1), recombinant TSP-1 (MFX+TSP-1), or a combination of both proteins (MFX+TSP-1+OP-1). Six and 26 weeks after surgery, the repair tissue and the degree of endochondral ossification were assessed by histochemical and immunohistochemical methods detecting collagen types I, II, X, TSP-1, and CD31. Microfracture treatment merely induced the formation of inferior fibrocartilaginous repair tissue. OP-1 stimulated chondrogenesis, but also induced chondrocyte hypertrophy, characterized by synthesis of collagen type X, and excessive bone formation. Application of TSP-1 inhibited inadvertant endochondral ossification, but failed to induce chondrogenesis. In contrast, the simultaneous application of both TSP-1 and OP-1 induced and maintained a permanent, nonhypertrophic chondrocyte-like phenotype within cartilage repair tissue. The data of this study demonstrate that OP-1 and TSP-1 complement each other in a functional manner. While OP-1 induces chondrogenesis of the ingrowing cells, TSP-1 prevents their further hypertrophic differentiation and prevents excessive endochondral ossification within the lesions.

Thrombospondin-1 prevents excessive ossification in cartilage repair tissue induced by osteogenic protein-1.

Hypoxia-inducible factors (HIF1α/HIF2α) are key transcription factors that promote angiogenesis. The overexpression of degradation-resistant HIF mutants is considered a promising pro-angiogenic therapeutic tool. We compared the transcriptional activity of HIF1α/HIF2α mutants that obtained their resistance to oxygen-dependent degradation either by deletion of their entire oxygen-dependent degradation (ODD) domain or by replacement of prolyl residues that are crucial for oxygen-dependent degradation. Although all HIF mutants translocated into the nucleus, HIF1α and HIF2α mutants inclosing the point mutations were significantly more effective in trans-activating the target gene VEGF and in inducing tube formation of endothelial cells than mutants lacking the complete ODD domain.

Deletion of the oxygen-dependent degradation domain results in impaired transcriptional activity of hypoxia-inducible factors.

Operative treatment of sternal fractures has become a matter of increasing interest. Anterior plating seems to be the most appropriate method for fixing sternal fractures. However, there are several concerns in relation to the operative procedure such as severe injuries to mediastinal organs, patient comfort and proper stabilisation, for example. This paper describes a safe method of anterior sternal plating using locked plate fixation with limited depth drilling.

Surgical fixation of sternal fractures: locked plate fixation by low-profile titanium plates--surgical safety through depth limited drilling.

The purpose of this study was to investigate integration and cellular outgrowth of native cartilage autografts transplanted into articular cartilage defects. Native cartilage autografts were applied into chondral defects in the femoral condyle of adult sheep. Within the defects, the calcified cartilage layer was either left intact or perforated to induce bone marrow stimulation. Empty defects served as controls. The joints were analyzed after 6 and 26 weeks by macroscopic and histological analysis using the ICRS II Score and Modified O'Driscoll Scores. Non-treated defects did not show any endogenous regenerative response and bone marrow stimulation induced fibrous repair tissue. Transplanted native cartilage grafts only insufficiently integrated with the defect borders. Cell death and loss of proteoglycans were present at the margins of the grafts at 6 weeks, which was only partially restored at 26 weeks. Significant cellular outgrowth from the grafts or defect borders could not be observed. Bonding of the grafts could be improved by additional bone marrow stimulation providing ingrowing cells that formed a fibrous interface predominantly composed of type I collagen. Transplanted native cartilage grafts remain as inert structures within cartilage defects and fail to induce integrative cartilage repair which rather demands additional cells provided by additional bone marrow stimulation. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Article	Year
Balser plate stabilization: an alternate therapy for traumatic sternoclavicular instability. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]\| PubMed ID: 12851582	2003
Multidetector CT of the paranasal sinus: potential for radiation dose reduction. Radiology\| PubMed ID: 17517938	2007
Role of hypoxia-inducible factor 1 alpha in the integrity of articular cartilage in murine knee joints. Arthritis research & therapy\| PubMed ID: 18789153	2008
Quantitative T2 mapping during follow-up after matrix-associated autologous chondrocyte transplantation (MACT): full-thickness and zonal evaluation to visualize the maturation of cartilage r... Journal of orthopaedic research : official publication of the Orthopaedic Research Society\| PubMed ID: 19133648	2009
Penetration of moxifloxacin into bone evaluated by Monte Carlo simulation. Antimicrobial agents and chemotherapy\| PubMed ID: 19223648	2009
Bone penetration of amoxicillin and clavulanic acid evaluated by population pharmacokinetics and Monte Carlo simulation. Antimicrobial agents and chemotherapy\| PubMed ID: 19307356	2009
Early repolarization, left ventricular diastolic function, and left atrial size in professional soccer players. The American journal of cardiology\| PubMed ID: 20691318	2010
Stop of loss of cognitive performance during rehabilitation after total hip arthroplasty-prospective controlled study. Journal of rehabilitation research and development\| PubMed ID: 21174253	2010
Chondromodulin 1 stabilizes the chondrocyte phenotype and inhibits endochondral ossification of porcine cartilage repair tissue. Arthritis and rheumatism\| PubMed ID: 21391200	2011
Thrombospondin-1 prevents excessive ossification in cartilage repair tissue induced by osteogenic protein-1. Tissue engineering. Part A\| PubMed ID: 21513464	2011
Deletion of the oxygen-dependent degradation domain results in impaired transcriptional activity of hypoxia-inducible factors. Transcription\| PubMed ID: 22223045	2011
Surgical fixation of sternal fractures: locked plate fixation by low-profile titanium plates--surgical safety through depth limited drilling. International orthopaedics\| PubMed ID: 24122047	2014
Limited integrative repair capacity of native cartilage autografts within cartilage defects in a sheep model. Journal of orthopaedic research : official publication of the Orthopaedic Research Society\| PubMed ID: 25470997	2014

Friedrich F. Hennig

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